physiological ecology

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Physiological ecology (animal)

A discipline that combines the study of physiological processes, the functions of living organisms and their parts, with ecological processes that connect the individual organism with population dynamics and community structure. See Population ecology

Physiological ecologists focus on whole-animal function and adjustments to ever-changing environments, in both laboratory and field. Short-term behavioral adjustments and longer-term physiological adjustments tend to maximize the fitness of animals, that is, their capacity to survive and reproduce successfully. Among the processes that physiological ecologists study are temperature regulation, energy metabolism and energetics, nutrition, respiratory gas exchange, water and osmotic balance, and responses to environmental stresses. These environmental stresses may include climate variation, nutrition, disease, and toxic exposure. For instance, climate affects animal heat and mass balances, and such changes affect body temperature regulation. Behavioral temperature regulation (typically, avoidance of temperature extremes) modifies mass and energy intake and expenditure, and the difference between intake and expenditure provides the discretionary mass for growth and reproduction. Mortality risk (survivorship) also depends on temperature-dependent behavior, which determines daily activity. Activity time constrains the time for foraging and habitat selection, which in turn influence not only mortality risk but also community composition. Animals are similarly constrained in their discretionary mass and energy by reduction in nutrition, which decreases absorbed food, and by disease and toxins, which may elevate the costs to maintain a higher body temperature (fever). See Behavioral ecology, Homeostasis

Physiological ecology (plant)

The branch of plant science that seeks physiological (mechanistic) explanations for ecological observations. Emphasis is placed on understanding how plants cope with environmental variation at the physiological level, and on the influence of resource limitations on growth, metabolism, and reproduction of individuals within and among plant populations, along environmental gradients, and across different communities and ecosystems. The responses of plants to natural, controlled, or manipulated conditions above and below ground provide a basis for understanding how the features of plants enable their survival, persistence, and spread. Information gathered is often used to identify the physiological and morphological features of a plant that permit adaptation to different sets of environmental conditions.

The environments that plants occupy are often subject to variation or change. The ecophysiological characteristics of these plants must be able to accommodate this or the plants face extinction. Given the right conditions, ample time, and genetic variation among a group of interbreeding individuals, plant populations and species can evolve to accommodate marked ecological change or habitat heterogeneity. If evolutionary changes in physiology or morphology occur on a local or regional scale, populations within a single species may diverge in their characteristics. Separate ecological races (ecotypes) arise in response to an identifiable, set of environmental conditions. Ecotypes are genetically distinct and are particularly well suited to the local or regional environment they occupy. Such ecotypes can often increase the geographical range and amplitude of environmental conditions that the species occupies or tolerates. Ecotypes may also occur as a series of populations arrayed over a well-defined environmental gradient called an ecocline. In contrast, if ecotypes are not present, some plant species may still be able to accommodate a wide range of growth conditions through morphological and physiological adjustments, by acclimation to a single factor (such as light) or acclimatization to a complex suite of factors which define the entire habitat. Acclimatization can occur when individuals from several different regions or populations are grown in a common location and adjust, physiologically or morphologically, to this location. Acclimation and acclimatization can therefore be defined as the ability of a single genotype (individual) to express multiple phenotypes (outward appearances) in response to variable growing conditions. Neither requires underlying genetic changes, though some genetic change might occur which could mean that the response seen may itself evolve. Acclimation and acclimatization may also be called phenotypic plasticity. See Plant evolution

Studies of metabolic rates in relation to environmental conditions within populations, ecotypes, or species provide a way to measure the tolerance limits expressed at different scales. These data in turn help identify the scales at which different adaptations are expressed, and enhance an understanding of the evolution of physiological processes. Combining observations and measurements from the field with those obtained in laboratory and controlled environment experiments can help identify which conditions may be most influential on plant processes and therefore what may have shaped the physiological responses seen. Laboratory and controlled environment (common garden) experiments also assist in helping identify how much of the variation expressed in a particular metabolic process can be assigned to a particular environmental factor and how much to the plants themselves and the genetic and developmental plasticity they possess. See Ecology, Ecosystem, Plant physiology

McGraw-Hill Concise Encyclopedia of Bioscience. © 2002 by The McGraw-Hill Companies, Inc.

physiological ecology

[‚fiz·ē·ə′läj·ə·kəl ē′käl·ə·jē]
The study of biophysical, biochemical, and physiological processes used by animals to cope with factors of their physical environment, or employed during ecological interactions with other organisms.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
References in periodicals archive ?
53-154 In Biology of the Reptilia, Volume 13, Physiology D Physiological Ecology. Gans, C.
His primary research areas include environmental toxicology and physiological ecology, and he holds faculty appointments at the University of South Carolina, the Medical University of South Carolina, and the College of Charleston.
Additional sections include "Conditions and resources" (two chapters) covering basics in physiological ecology in both terrestrial and aquatic systems, "Individuals, populations, communities, and ecosystems" (seven chapters), and concluding with "Applied issues in ecology" (three chapters), covering sustainability in agricultural systems, pollution, and conservation biology.
Physiological Ecology of Estuarine Organisms, University of South Carolina Press, Columbia, South Carolina.
longirostris, we synthesized quantitative data from the literature on the physiological ecology of these species.
These estimated retrospective net differences between populations in standardized selection gradients agree with the predictions from the physiological ecology for selection on these traits and the selection gradients observed in a companion study (Dudley 1996).
Undeterred from those early career aspirations, she has been investigating the physiological ecology of marine animals and the effects of toxic chemicals on physiological processes in marine animals for the past 25 years.
He was a global leader in the physiological ecology of phytoplankton.
Chapter eight, "Physiological ecology," explores the adaptive features of bryophytes to abiotic environmental factors especially water, light, mineral nutrition, and temperature.
Research activities have centered on both aquatic and terrestrial habitats and has involved numerous investigators who have focused on many areas of science (e.g., Wildlife Ecology, Conservation, Aquaculture, Physiological Ecology, Behavioral Ecology, Reproductive Biology, Ecological Genetics, Biogeography, and Systematics).
This book is not intended as a teaching text but makes a strong contribution to the literature of grassland ecology similar to that of other recent works: Wildland Plants: Physiological Ecology and Developmental Morphology edited by D.J.

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